P0118 OBD II Trouble Code Engine Coolant Temperature Sensor Circuit High Input

Symptoms of P0118 OBD II Trouble Code

  • Very poor fuel economy
  • A no start condition
  • Vehicle may start, but run very poorly, blowing black smoke, running very rough and misfiring
  • Illumination of MIL

Common Causes of P0118 OBD II Trouble Code

  • A bad connection at the sensor
  • An open in the ground circuit between the ECT sensor and the PCM
  • A short in the voltage feed between the sensor and the PCM
  • A bad PCM (less likely)
  • A bad temperature sensor (shorted internally)